SCARY HANDLING AT HIGHWAY SPEEDS!!!!!!!!!!

[rideapony]

Hi all

1990 Mustang GT:

I'm having a lot of issues with my ride handling at highway speeds, the car wanders so bad that it is scarry!!!

This is what I have on the steering and suspension:
SN95 spindles, Polyurethane red lower control arm bushings, Poly sway bar bushings and links, Bilstein struts and rear shocks with poly mounts, Eibach sportsline springs kit with poly issolators, offset Poly rack and pinion bushings, Hotchkis caster camber plates, 245/45/17 Firestone tires on 17x9 cobra R wheels.

I went thru some troubleshooting but haven't seen improvements at all:
Replaced the right inner tie rod end (It was shot) and then took it to alignment using Hotchkis suggested settings.
Inspected lower ball joints, tie rod ends and steering rag joint (everything is good).

I don't feel any bumpseeter issues but I noticed my front tires are showing wear on the inside, camber seem ok (visually) so maybe toe alignment could be out of spec.

This wandering issue is been there since I remember but I'm tired of it and would like to fix it once and for all or at least minimize it. I was reading about "Tramline" or something like that but how to fix that?

My steering and suspension feels very tight with no slopinness or deflection, so why it wanders so hard? Please give me your ideas, I need them bad!!!

Thank you, Nick

 

[rideapony]

Please help!!! Anyone out there....?

 

[stykthyn]

I have the same issues minus the tire wear. at highway speed its looking to grab a dip in the road and shoot off into the other lane. Other than keeping a kung fu grip on the steering wheel I havent found a way to fix this yet. I know jeeps use a hydraulic assist cylinder on the steering rack to help when larger wheels are installed, I am curious if the same can be done for a mustang.

 

[rideapony]

Thanks stykthyn for your comments and suggestions.
I totally agree, I really have to use some power to hold the steering wheel and have to react quickly in order to keep the car inside the lane in straight line otherwise this thing would run out of control!!!

It almost seems and feels like tha camber somehow gets extremely negative when the tires roll on top or bellow the road crown and is when it gets really unstable . I asked the shop to do the front end alignment per Hotchkis suggested settings but I might have to go back and have them double check the specs.
Toe: 1/16" IN Total Toe
Camber: 1/2 Degree Negative
Caster: 2 Degrees Positive

I hope to see more comments and suggestions on how to find solution for this awful issue

Nick

 

[jrichker]

Increasing the caster so that the top of the strut rod tilts backward as much as possible will reduce road wander and the tendency of the car to dart off in one direction or the other. Shoot for 3 ° to 3.5° caster. Try to get both sides aligned with the same amount of caster.

 

[rideapony]

jrichker, somehow I knew you were going to chip in with suggestions because you always help us and I thank you for that!!!
That makes sense, I will try to reset the alignment settings with what you suggested. Thanks for the help! Will see how this thing works.

Nick

 

[MFE92]

Are you running drag radials on the back? They'll make the car wander in a very disconcerting way.

How old are the front tires? The older they are, the more likely they are to wear in a cone-shaped fashion, and when they do, they tramline like crazy. Fresh tires can make a huge difference.

As good as negative camber is for handling, it also makes tramlining worse, because it encourages the tire to try to climb the wall of the rut it's in.

But the fundamental problem with these cars and tramlining is due to the scrub radius built into the front suspension. The contact patch of the tires is outboard of where the steering axis intersects the ground, which means the tires have a lot of leverage against the steering axis, and when one tire encounters a road irregularity, such as trying to climb the wall of a rut, it'll tug the steering around with it.

So: Have a look at the other inner tie rod end. Consider replacing your tires. Consider your caster and camber settings.

 

[rideapony]

MFE92 I appreciate your ideas.
The tires are not that old. And I made a mistake at the beginning, I'm running BFGoodrich
g-Force Super Sport A/S
245-45-ZR17 95W
And not Firestone as I stated. The other inner tie rod has no play. Certainly I'm learning about that condition on fox body stangs.
I'll try to get new tires and review/update my aligning settings.

Thank you, Nick

 

[larrym1961]

I had a set of 245/45/17 tires all the way around on my '87 and seemed to have a wandering problem with it. I went to the next size smaller tire up front, a 235/45/17 and the wandering stopped. Possibly my front end set up did not like the wider 245 tire up front.

 

[rideapony]

larrym1961, thank you for chipping in!!!
I would like to have same tire sizes on the four corners to be able to do rotation, but of course I will follow your suggestion as a last resort.

Yesterday I decided to start with jrichker's suggestion of adjusting the caster; for this I loosened the two hex head bolts on my Hochkis caster/camber plates and just moved both struts until they stoped, then I measured the distance from the top of the struts to a reference point on the firewall ended at almost the same exactly dimension.

Well today I went for a ride, although I didn't drive on a really rough stretch on the highway where this thing was soo wild, I was really surprised how stable was on a straight line. I guess I will have to drive that rough stretch to see how it feels.

Another thing I noticed, it was a bit harder to turn and required a bit more force to keep turning on a wavy road as the car tries to go on a straight line (I wasn't surprised because I was expecting this to happen). I have no idea where the front alignment is at this point and maybe it has a tad too much positive caster, but I think I'm going in the right direction.

Again the caster alignment I ordered to the shop based on Hotchkis siggestions was 2 degrees positive. Until now I'm thinking that maybe that was too shallow because I have SN95 spindles and stock caster for those cars is 3.0 to 3.5 degrees positive. I want to believe that this is my problem but will find out soon and will post the results.

Nick

 

[Gearbanger 101]

What kind of shape are your wheel bearings in. I noticed you listed checking everything but them.

Keep in mind...a tire that has started to wear on one particular spot, will continue to wear on that spot, even if the algnment issue is fixed. The damage will have already been done and the tire will continue to wear uniformly from that point. If you can't swap them from front to back, then I would suggest replacing the tire if the wear is that bad.

 

[rideapony]

Thanks Brian for you post.
Bearings give a very distinctive feeling and no there is no play on them. The only sloppiness was on the inner tie rod end which I already replaced.

The wear I noticed on the front tires is not that horrible and since I have the same size in all corners I did the rotation already. Yes I know the damage has already happened and will have to think on new tires. Of course money is an issue but have no choice, have to do that soon!!!

Nick

 

[rideapony]

Hi all
Well I took my ride to the shop for alignment and I was very surprised when the guy told me that he couldn't achieve all the settings as I requested on the caster and camber specs:

Camber I asked 0.5 degree negative but he said he ONLY was able to achieve -0.7 and -1.0
Caster I asked 4.5 to 5.0 Degrees positive equally on both sides but he ONLY was able to achieve 2.7 and 3.0 degrees
Really???? even with the Hotchkis caster/camber plates??? I don't know if to believe it or not but I still have my doubts about the skills of those guys, they did the alignment at Sears. Do you guys think I made a mistake taking it there?

Since I have SN95 spindles I wanted to set my caster based on this article that might help with my wandering problem.
http://www.miracerros.com/mustang/t_suspension3.htm
....At 4 degrees caster or less, you will gain positive camber when the wheel is turned (not good). More than 4 degrees of caster will produce negative camber gain when the wheel is turned (good). People often set up their cars with more than 4 degrees of positive caster for that reason. Five or six degrees of caster is optimal on a street-driven 94+ Mustang.

Please if you can comment on this and possibly bring more ideas.

Thank you, Nick

 

[Bullitt347]

Sub frame connectors help tremendously as well, and there is no substitute for a quality alignment. Someone who knows what they are doing (not sears) is worth the extra $ spent. I spent $225.00 for the alignment on my Mustang and it was worth every penny. It is spot on, he was able to get it into the proper specs and this cars goes dead straight regardless of ruts and I have no tire wear issues.
If the guy doing the alignment only knows how to follow the alignment machine "directions" then he really does not know anything about proper vehicle alignment. Sometime settings outside of the "specs" are actually better. You have to have someone who knows what ackerman is, what bumpsteer is and how caster ( and caster split) and camber can cause or correct alignment issues. If the alignment person cannot speak to these things intelligently, then it is time to find someone else. Such knowledge and application of the knowledge is usually not available at the $69.95 discount alignment center.

 

[larrym1961]

Sub frame connectors help tremendously as well, and there is no substitute for a quality alignment. Someone who knows what they are doing (not sears) is worth the extra $ spent. I spent $225.00 for the alignment on my Mustang and it was worth every penny. It is spot on, he was able to get it into the proper specs and this cars goes dead straight regardless of ruts and I have no tire wear issues.
If the guy doing the alignment only knows how to follow the alignment machine "directions" then he really does not know anything about proper vehicle alignment. Sometime settings outside of the "specs" are actually better. You have to have someone who knows what ackerman is, what bumpsteer is and how caster ( and caster split) and camber can cause or correct alignment issues. If the alignment person cannot speak to these things intelligently, then it is time to find someone else. Such knowledge and application of the knowledge is usually not available at the $69.95 discount alignment center.

Les Schwab did a great job on the installation of my Eibach springs and my alignment, but then again they also do custom suspensions too as opposed to Sears.

 

[rideapony]

Thank you Bullit347!!!
Welded sub-connectors will be my next step. And I agree sears are not up to the task but I'm running out of options on where to take my car for a good alignment here in Santa Rosa California. I already went thru 5 places here in this area including Les Schwab and Spring Works!!!
Custom suspension alignment at Les Schwab??? Really? At least the one here in Santa Rosa, Ca did a crappy job, and they where whining and crying all the time telling me "Oh, you don't have stock suspension, you have too many aftermarket parts" :o well that's why it is custom suspension!!!

Hey larrym1961 please don't feel bad and just want to clarify that I'm not putting your comment down it's just that I tried those guys and didn't work in my specific situation.

Really it is frustrating and I'll buy the sub-connectors and take the car to a frame shop have them weld and then do the alignment.

Thank you all, Nick

 

[Gearbanger 101]

I spent $225.00 for the alignment on my Mustang and it was worth every penny. It is spot on, he was able to get it into the proper specs and this cars goes dead straight regardless of ruts and I have no tire wear issues.

Wow.....$225 for an alignment!?! They saw you coming. I can just imagine their justification for that price and their argument as to why their alignment is so much better than the others. I got one of those $69.95 alignments from a local reputable shop you just shunned and my car tracks straight as an arrow....as does my truck and my previous car before it.

 

[Bullitt347]

Wow.....$225 for an alignment!?! They saw you coming. I can just imagine their justification for that price and their argument as to why their alignment is so much better than the others. I got one of those $69.95 alignments from a local reputable shop you just shunned and my car tracks straight as an arrow....as does my truck and my previous car before it.

How much would it have cost you if the guy performing the alignment had to shift the tubular K-member that you just installed in the chassis, and also to square up the rear differential in the chassis so all 4 wheels were tracking true? This guy handled all of the aftermarket stuff i installed and made it work. I would say I got a bargain and I am a good friend of the person who performed the work. No he did not "see me coming" I got excellent service at a fair price and I would venture to say that you could not find anyone more competent when it comes to setting up a chassis.

EDIT: I do know this for sure and for certain: your $69.95 alignment guy would not/could not have aligned my car for that price. I would have received the phone call about the "unexpected charges" that would be due. If all I want is a toe set, then I will save the $69.95 and do it myself.

 

[Bullitt347]

Thank you Bullit347!!!
Welded sub-connectors will be my next step. And I agree sears are not up to the task but I'm running out of options on where to take my car for a good alignment here in Santa Rosa California. I already went thru 5 places here in this area including Les Schwab and Spring Works!!!
Custom suspension alignment at Les Schwab??? Really? At least the one here in Santa Rosa, Ca did a crappy job, and they where whining and crying all the time telling me "Oh, you don't have stock suspension, you have too many aftermarket parts" :o well that's why it is custom suspension!!!

Hey larrym1961 please don't feel bad and just want to clarify that I'm not putting your comment down it's just that I tried those guys and didn't work in my specific situation.

Really it is frustrating and I'll buy the sub-connectors and take the car to a frame shop have them weld and then do the alignment.

Thank you all, Nick

Just make sure the car is on a drive on lift when the sub frame connectors are welded in.

 

[Gearbanger 101]

How much would it have cost you if the guy performing the alignment had to shift the tubular K-member that you just installed in the chassis, and also to square up the rear differential in the chassis so all 4 wheels were tracking true? This guy handled all of the aftermarket stuff i installed and made it work.

Considering the OP still uses his stock K-Member, A-Arms, non adjustable upper and lower rear control arms, etc. I would say the standard alignment would not only be more than fine for his needs, but his only option considering none of those other areas are adjustable with the factory equipment.

Not exactly a "get what you pay for" situation that you initially alluded to, but instead a "it needed to be to, to set it up to spec at all" necessity in your case. Prettttty important details do be leaving out of your previous post, don't you think? Not exactly just an "alignment" job for that price.